A trend graph display method described in a certain patent document calculates an average value of data that is collected based on a predefined time range, and overlays and displays the average value on a trend graph. In this example, calculation results change as the time range shifts, however, a type of the displayed indicator is always the same.
Another patent document discloses an example of using a scroll display in order to display time-series data that is longer than the width of a screen. This example enables the time-series data to be seen easily, however, other information is not obtained.
Patent Document 1: Japanese Laid-open Patent Publication No. 09-244618
Patent Document 2: Japanese Laid-open Patent Publication No. 07-056961
Therefore, there is no technique for providing a user with information that is suitable for a dominant state among a sleep state and a non-sleep state.